Attrition in controlled experiments
AttritionIn a controlled experiment, attrition is the loss of participants from the study due to death, illness, relocation, or other reasons. Attrition and biasAttrition can lead to bias if it is not random. Types of attritionThere are three types of attrition: Differential attrition occurs when there is a difference in the rate of attrition between the treatment and control groups. Selective attrition occurs when there is a difference in the characteristics of those who remain in the study versus those who do not. Informative attrition occurs when the characteristics of those who leave the study are related to the outcome of the study. |
methods to address attrition in controlled experimentsThere are a number of ways to address attrition in controlled experiments, including: -randomization: This ensures that participants are equally likely to be included in the study, regardless of their attrition rate. -matching: This ensures that participants who are similar on key variables are included in the study, which can minimize the impact of attrition. -inclusion/exclusion criteria: This can ensure that only participants who are likely to complete the study are included, which can minimize the impact of attrition. -data imputation: This is a statistical technique that can be used to estimate missing data, which can minimize the impact of attrition. |